Engine fuel control means



Feb. 7, 1950 L. E. ENDSLEY ETAL 2,496,458

ENGINE FUEL CONTROL MEANS Filed April 1, 1946 2 Shets-Sheet l INVENTORS Lou/s E E NDSLEY JAMES E. Jusrus A TTORNEY Q Li.

'Feb. 7, 1950 L. E. ENDSLEY ETAL 2,496,453

ENGINE FUEL CONTROL MEANS Filed April 1, 1946 2 Sheets-Sheet 2 PUMP I8 6 PUMP l9 4 s RACK POSITION MuNvno 13nd w; INVENTORS Louis E. ENDSL'EY JAMES E. Jusrus TE 5 m1 1 ATTORNEY FIGZ Patented Feb. 7, 1950 ENGINE FUEL CONTROL MEANS Louis E. Endsley, Pittsburgh, Pa., and James E. Justus, Beloit, Wis., assignors to Fairbanks, Morse & Co., Chicago, 111., a corporationof Illinois Application April 1, 1946, Serial No. 658,674

H 3 Claims. (Cl. 123--140) This invention relates to improvements in the fueling of internal combustion engines, and has particular reference to improved control mechanism for the fuel delivery apparatus of engines such as Diesel engines of the opposed piston type.

It is well known in Diesel engine practice and particularly in the instance of opposed piston Diesels, to employ for the purpose of improved combustion efficiency, two or more fuel injectors in each cylinder arranged as in diametrical or other suitably spaced relation to afford a uniform and more effective fuel distribution in the cylinder combustion space. However, in connection with fuel systems utilizing airless or solid fuel injectors of well-known or prevailing construction, it has been found in practice that during engine operation under no load, idling speed and sometimes under light load conditions with engine speed only slightly above idling, fuel delivery through the injectors tends to be in excess of that quantity necessary merely to maintain engine idling or low speed operation. Where the engine is employed as a prime mover for railway locomotives, as switch and transfer locomotives in particular, frequent and many times relatively long periods of engine operation at idling or low speed, are encountered in normal locomotive use, so that the problem of excess fuel consumption or fuel wast- 'age during idling in particular, is of major importance in Diesel locomotive practice. In fact, if not prevented, th excess fuel not consumed in the normal combustion process at idling or low speeds, ultimately will leak past the pistons into the engine crankcase and there mix with the lubrication oil with consequent dilution of the latter to a more or less serious degree. In time, the accumulation of fuel oil in the crankcase may reach proportions dangerous for obvious reasons, to further engine operation. Accordingly, it is a principal purpose of the present invention to provide in operative association with the fueling apparatus of a Diesel engine of opposed piston type in'particular, employing two or more fuel injectors in each cylinder thereof, control means of a novel and effective character, for regulating engine fueling in a manner such as will avoid the condition above expressed.

Stated more particularly, the present improvements afford an engine governor responsive control mechanism for regulating fuel pump delivery to the injectors of the cylinders such that during no load, idling or light load, low speed operations of the engine, fuel will be delivered through less than all of the injectors, as only one injector in each cylinder, and in quantity sufficient merely to continue idling or low speed operation. Under load operation of the engine, the control mechanism functions in response to governor action, to determine pump fuel delivery to all of the injectors, and to effect at least at full load, an equal fuel quantity injection by the injectors in each cylinder.

Another object of the present invention is to embody in a fuel delivery control mechanism for the purpose indicated, means for actuating the control in the event of failure 'of normal oil pressure in the engine lubricating system, to cause an immediate reduction in fuel pump delivery such as will stop further operation of the engine.

The, foregoing and other objects will appear readily from the following description of a presently preferred embodiment of the invention as exemplified in the accompanying drawing, wherein: v v

Fig. 1 is a fragmentary horizontal section of an engine embodying the present improvements, the view showing one cylinder, injectors and fuel pumps in diagrammatic elevation;

Fig. 2 is a view similar to that of Fig. 1, but illustrating the control mechanism in the position of no-fuel delivery adjustment of the fuel pumps;

Fig. 3 is a detail view of a part of the governor operated mechanism, as taken along the line 33 in Fig. 1, and

.Fig. 4 illustrates graphically, fuel quantity delivery by the opposite pumps corresponding to rack positions, and indicates the relativ positions of the racks throughout engine operation.

In the drawing there are shown in somewhat diagrammatic manner, onlysuch parts of a Diesel engine of an opposed piston type, which are considered essential or desirable to a full understanding of -the present invention. The

. engine frame In adapted for the support of the cylinders, one of which is shown at l I, includes opposite) side walls [2 and II and transverse frame members two of which appear at l5 and I6. Arranged in suitable position on opposite sides of the cylinder H' are fuel pumps I8 and I9, which may be alike and of any well known construction. By present preference, the pumps are of reciprocating plunger type, each driven by the engine as through a camshaft (not shown) and regulatable as to fuel quantity delivery by angular adjustment of its plunger through a rack control element indicated at 20. Fuel delivery is effected from pump l8 through a conduit 22 to an air-less injection valve 23 in the cylinder II, for injection to the cylinder combustion space. In like manner, the

pump I 9 delivers through a conduit 25 to an injectionvalve 24iocatedintbecylinderpreferably diametrically opposite the injection valve 28.

Whilebutonecylinder llishereahowmin enginesof more thanone cylindeneaehcylinder willhaveassociatedtherewithalikepairoffuel pmnpsandcylinduinjectoraarranmedls deseribedfortbecylindershown. Thegroupor bankofpumpsononelongitudimlaideofthc engine,asontheri8hthandsideasviewedin element ofeachpumpinthebmhhluihbly adjustablyconnectedtoarod.2lbyanoperating pIacementmovementsofrodILtherackofeach pumpwillbeactuatedtoadjustthepumpontput. Thepmnpsinthelefthandbanksimilarlyhave theirrackelementslladjustablyconnectedtoa 'eommoncontrolrodilthislatterbeingimder of rod 3.. Operatively connecting the lever end 42 andtheendflofrodllisalinkelementfl suitably pivotally secured to the rod and lever as shown. At the opposite lever end 3|, the lever connectiontotherodll ismadebymeanspermitting a limited pivotal movement or overtravel'of the lever without corresponding movementftherod2Lasforapurposetoappear. The means referred to comprises by present preference, a member 46 pinned or otherwise suitably pivotally connected at one end 4'I, to the end 3. of rod 21, and pivotally carried on the lever II by alink4l.thelinkbeingpivotedtothelever ata point inwardly adjacent the lever end 38, and to thememberflatapointinwardiyadjacentthe mid II of the latter. Carried by the end SI of member 4| is an adjustable distance piece, shown as a cap screw ll arranged for abutment with the lever 3|. A suitable compression spring I! having its ends seated in recesses or pockets i4 and II formed respectively, in the lever 3| and member 4|, serves to retain the parts in normal operative relation, as with the cap screw in abutment with the lever to afford a substantially rigid connection between the lever and rod 21 throughout normal fuel regulating operation of the mechanism. However, in the lever actuation of rodllinthedircctionasindicatedbythearrow I. to reduce the fuel output of the pump to zero fuel delivery (Fig. 2), the connection as desa'lbedwillfunctiontopermitpositioningofthe pump racks at "zero fuel positions. Thereafter upon further lever movement in the same directionforreturningtheoppositebankofpmnpsfo aerofuelconditionaswillbereferredtobereafter, therodfl atsuchtimebeingheldagainstfurther movementbyabutmentofthepumprackswith yield. compressing as the end II of the lever tl approaches the end I! of rod 21, while the member 46 pivots relative to rod 21, thus allowing the desired over-travel of the lever II as to the p sition shown in 2.

Pivoting of the lever II in the direction to increase fuel pump output, may be adjustably limited say to a position determining full load pump delivery, by a stop element or cap screw 5| in the frame l5, Positioned for abutment by a projection 6. on the lever.

Governor connection to lever ll preferably is made at the lever end 42, and comprises a yoke member I pinned to the lever at $2 and adjustably threaded lengthwise into one end of a bar 64. The opposite end 65 of bar 64 is freely projected through an aperture 86 transversely through the central part of a pivot pin 6., the latter being supported at its ends in spaced arms 68 forming a lever the hub portion of which (Fig. 3) is suitably secured or keyed upon one end of a shaft 15. A nut and washer It on the free end of bar 64 when in abutment with pin 68, determines a positive actuating connection serving in one direction of rotation of shaft 12, to produce pivotal displacement of the lever 3|. Pivotal movement of the lever in the opposite direction by shaft rotation opposite to that mentioned, is here effected, however, through a yieldable element comprising a compression spring 14 bearing between a cap flange ii on the bar 64 and a flanged washer II, the latter abutting the pin SI.

Shaft 15 is suitably rotatably journalled by bearings II in the opposite frame sides I: and I4, and projects at It for connection by a lever Ii,

t0.the governor 26. Thus the lever system as now described, is under direct control of the governor, for determining fuel delivery regulation of the several fuel pumps in a manner now to be fully pointed out.

. Before proceeding with the operation, it is to be noted that the rack element 20 of each pump is provided with graduations arranged longitudinally over an exposed surface thereof and numbered from zero to seven (Fig. 1), while a pointer .4 fixed to the pump frame is associated with the graduations as shown. The pump assembly is adjusted such that when the rack 20 is positioned to register the zero graduation with the pointer, the pump plunger will be thereby conditioned for no-fuel delivery to the injector, and further such that for example when the rack is actuated to register graduation No. 3 with the pointer 84, the pump plunger thereby rotated to an extent corresponding to the rack displacement from zero to the No. 3 graduation, will be conditioned for fuel delivery through the associated injector in quantity sufficient merely to maintain engine operation at no-load, or at most, under a minimum load, low speed condition. Continued rack displacement such as to register graduation No. 7 for example, with the pointer 84, thereby conditions the pump for full-load fuel delivery.

Turning now to the operation of the system, when the engine is not in operation, the mechanism is positioned (Fig. 2) as determined by the inactive position of the governor 26, to dispose the control rod ll such as to locate the racks 24 of the left hand bank of fuel pumps, to register the zero graduation of each with the associated pointer 84. Similarly, the racks 20 of the right hand bank of fuel pumps will be positioned through rod 21, to register the zero graduation or suitabje stops (not shown), the spring I! will Tl each with the associated pointer 84, the yieldable w connection between the rod "and the-pivot bar or lever 3|, asmpnstituted by the elements 46, 487 and spring 62,,being at this time in what may be called a collapsed condition such that with the lever end ll relatively closely adjacent the end 39 of rod 21, the member 46 will be pivotally disthe stop element 5| is out of engagement with the lever 3|, as appears inFlg. 2. Now upon starting of the engine and adiustmentgf the governor 29 in a well known manner, to determine for example, normal no-load idlin of the engine, the lever 3| will be pivotally actuated by the governor through the shaft 16 and the described operating connection between the shaft'and lever 3|, to displace the control rod 39 sufficiently to cause actuation of the pump racks 29 in the left hand pump bank, to register graduations No. 3 with the fixed pointers. Pivoting of the lever 3| to this extent however, does not .effect movement of rod 21 and the connected racks of the right hand bankof fuel pumps, from the initial no-fuel delivery positions'of these elements because as the end 38 of the lever moves. away from the end 39 of the rod 21, the member 46 pivots about its connection to rod 21 until the stop element 5| engages the lever 3|, the latter obtaining (according to adjustment of the stop 5|) when the lever 3| is in the position to determine the aforementioned idling fuel delivery by the left hand bank of pumps. During this phase of lever placed relative to lever 3| to ,a position wherein the graph 86 indicates the same with respect to the pump l8, but shows the'greater rate of change of rack position of the latter pump in respect to that of pump l9; .From the graph, it appears that at engine idling, the rack of pump I9 I is at position 3, while the rack of pump I8 is at for example, the lever 3| in response to governor I actuation thereof, is pivoted in the direction to displace rod 39 to an extent such as to register the No. 7 graduation of each pump rack in the left hand pump bank, with the associated pointer 84 (Fig. 1). In this instance, rod 30 is moved from the idling position wherein the No. 3 graduation of each pump rack 2|) is in register with its pointer. As this takes place, the lever also actuates the rod 21 inthe direction to cause fuel delivery operation of the right hand bank of pumps. Since the portion 36 of lever 3| which is connectedto rod 21, is the longer arm of the lever, the resulting displacement of rod 21 will be greater than that of rod 39. In the present example, the

relative lengths of the lever}; arms 36 and 49 then will be in registry with its pointer 84. consequently, underfull load the fuel injection at each cylinder will be equally divided between the two injectors therein. The foregoing is-illustrated by Fig. 4, wherein the fuel quantity delivery.

by pump |9 varies with rack position substantially in accordance with the graph line 86, while load operation of the engine, both pumps are in operation with relative fuel quantity delivery in accordance with the graph lines, up to full load fuel delivery when the pumps titles of fuel.

It will be appreciated now that the present improvements afford a governor responsive 'fuel control mechanism which is operative to determinefuel delivery through only one injector in each cylinder at engine idling or low speed operation. The arrangement thus enables the most eflicient operation ofthe fueling means at idling for example, precluding the admission of more fuel than is necessary merely to maintain the engine in operation under idling condition, thereby avoiding fuel wastage and crankcase lubricating oil dilution by fuel oil, as would otherwise occur. Above idling, the mechanism determines in accordance with governor setting, fuel delivery through all of. the cylinder injectors, and effects at least at full load operation offlthe engine, equal quantity fuel injection at the injectors in each cylinder.

In the present embodiment of the invention, there is included a safety device effective to cause a reduction in or stoppage of fuel delivery by the deliver equal quan- .pumps-in' the evento'f abnormally low oil pressure or pressurefailure in the engine lubricatinglever 3 and a piston member 92 operable therein.

The cylinder head or cap 94 is centrally apertured at 95 to accommodate a shaft-like element 96 zero setting. Thus fuel delivery to the cylinder projecting therethrough, the element 96 being carried by the piston 92 and serving as a piston guide as well as the lever contact'element of the device. A cap screw or the like 98, adjustably carried on the lever 3|,"is positioned for engagement by the exposed end 199 of element 96 upon piston actuation as will be presently described. A shaft-like extension I92 from the opposite side of piston 92, is extended through the end portion |03 of the cylinder 9| and cooperates with element 96 to constrain the piston 92 to a. straightline displacement in the cylinder. Extension 02 also affords a shoulder |0l which in engagement with the cylinder end I93, determines the in-' active position of the piston. The piston is biased in the direction to engage the element 96 with the lever cap screw 98, by a suitable compression spring I06 arranged as shown, but normally is retained in the inactive position shown (with the spring under compression) by lubricating oilunder pressure admitted to the cylinder 9| through a conduit I01 leading from any suitable producedisplacementoftherodsflandtlmch asto'actuatetheraeksofthesevu'alfuelm in the direction to cause fuel-ddivery reduction orcessationatthepumps. 'I'heenginethuswill stop, and since the safety device will hold the lever against fuel-increasing t until the piston l! is retracted-by normal lube oil pressure, the engine cannot be Operated again until the cause of. lube oil pressure failure is ascertainedandcorrected. Itistobenotedherethat the engine shutdown operation of the device .0 as effected through the lever 3 i, is independent of the governor control of lever II, this being facilitatcd by the yieldable connection between the governor actuated shaft 12 and the lever 8|, as afforded by the spring ll.

Having now shown and described the invention as to a presently preferred embodiment thereof, what we desire to claim by Letters Patent is:

1. In an internal combustion engine, a cylinder, at least two fuel admission valves therefor, a fuel supply pump individual to each of said valves and includrng a control element operable to determine the fuel output of the pump, and control means for said pumps, said control means including a pivoted member, providing opposite long and short arms, engine speed responsive means for pivotally actuating said member, a positive connection between the short arm of said member and the control element of one of said pumm, effective to operate the control element for determining fuel output by the pump in direct proportion to displacement of the short arm throughout pivotal actuation of said member by said speed responsive means, and connecting means including a lost-motion device; between the long arm of said member and the control element of the other pump, effective only after a predetermined initial actuation of said member, to operate the control element of said other pump for determining fuel output by the pump in proportion to displacement of the long arm in pivotal movement of the member beyond saidinitial actuation thereof.

2. Fuel control means for an internal combustion engine providing a. cylinder, at least two fuel admission valves therefor, and a fuel supply pump individual to each of the valves and including a control element operable to determine the fuel output of the pump, said control means comprising a pivotally supported lever member providing a short arm and a long arm, means connecting said short arm to the control element of one of said pumps, means including a lost-motion device, conncctng said long arm to the control element of the other pump, and engine speed-responsive means for pivotally actuating said lever member.

3. The combination with an internal combustion engine providing a cylinder, at least two fuel admission valves therefor, and a fuel supply 8 pumpindividualtoeachofsaidvalmwhcreh eachpumpincludesancnginedrimcondsm strokeplungerandcontmlelementoperabletc varytheangularpositicnoftheplungu-forregulatingpumpmeloutmrtbetweenno-fueland maximumfueldellverytotheamociatedvalveol pumpcontrolmeamcompriaimalubatanthlly rectilinear member pivotally supported intermediateitsenmmchastodeflnealhortarm andalongarm,mcausprovirlingapositiveciinnectionbetwemsaidshortarmandthecmtrol elementofoneofsaidpummmeamlnclndiin alost-rhotlondevice.providingabetweensaldlongarmandthecontrolelementof theotherpummsaidmemberinaniniflalpuition,servingthroughsaidineansto positionthepumpcontrolelementstodetermme theangulsrpositionsofthepumpplumenior no-fueloutputanduponpivotalactuationof themembertoapredeterminedestentfromlts initial position,to.eilectthroughsaidsbortarm, operationofthepumpcontrolelementoonnected thereto, to regulate the angular position of the plunger -in said one pump for fuel delivery to its associated valve, said lost motion device durlr said actuation of the member, serving to prevent operation of the pump control element connected tothelongarmofthemember,wherebysaid other pump remains regulated for no-fuel delivery, said member and connection means being effective upon pivotal actuation of the member beyond said predetermined extent, to operate said pump control elements concurrently, for regulating the pumps to determine fuel delivery thereby,saidlongarmservingtooperatethe control element of said other pump at a rate greater-thantherateofoperationof the'control elementofsaidonepumpbytheshortarmof the member, such that regulation of both pumps for maximum fuel delivery is attained simultaneously, and engine speed-responsive means for pivotally actuating said member.

IDUIS B. m. JAIIE B. JUSTUB.

REFERENCES CITED The following references are of record in the file of this tmrrnn s'ra'rss ra'rsm's Great Britain Mar. 12, 1934 

